Embracing Mobile 3D Laser Scanning

"Technology is advancing so quickly that it's slowly replacing the surveyor." These concerns have already been voiced over and over as LiDAR scanning becomes more accessible. The most recent advance in scanning is terrestrial mobile LiDAR scanning (TMLS). This technology collects survey-grade data at highway speeds and at traditional survey costs, and in the transportation discipline this is a safer means of data collection while reducing risk for the whole project. But  http://b3.zcubes.com/v.aspx?mid=11631620  has surveyors questioning the longevity of these profession. What is seen as a threat because of efficiency should be embraced to ensure that surveying to survive. Land surveyors are increasingly missing out on surveying work because they're not advancing in current measurement technologies. Understanding and appropriately responding to non-traditional ways will significantly contribute to the success of the surveying profession and to the customers you serve.

Changing a Mindset
Historically, improvements in the surveying profession are the usage of real-time kinematics (RTK) and global positioning systems (GPS) replacing field crew members. The robotic total station was another scientific invention to assist survey professionals that led to shedding pounds crews. So did the calculator for field trig values and computers for CAD drawings, but eventually they too were accepted and are trusted today. The profession adjusted.

Now mobile 3D laser scanning is creating a new apprehension from an over-restricted view of the profession, although TMLS does not have to be viewed as another replacement. The future of the surveying profession continues to be viable if the technology can be used as "another tool in the toolbox." Hans Hess, former CEO of Leica Geosystems, one of the major producers and suppliers of both survey field equipment and static laser scanners, says that he encounters this attitude. "Sometimes I hear our customers say, 'Well, the surveying profession is dying and there is no future for all of us.' The need for geo-information is tremendous, and growing; geo-information has to be more up-to-date, more 3D, more accessible online, and so on. There are not many industries that offer so many exciting prospects."

Understanding the Technology
Technology is continually changing, and so must the surveyor's tools. The finish product is only as good as the original field data gathered. TMLS systems measure thousands of points another while traveling at highway speeds. The info gathered are complete 3D images of the area being measured. What used to take months now takes just a few hours in the field. The surveyor or CAD technician can extract the needed top features of this data at work at the desktop. Because the surveyor is been trained in spatial recognition, virtually walking the website becomes a benefit to the info extraction process. This technique allows the surveyor to extract data in more areas than he would have performing traditional shots every 25 feet.

Accompanying video documentation and digital images permits an improved QA/QC process through a recorded visual reference. This enables the surveyor to return to the website at the desktop instead of revisiting the field to create additional observations. Combined, this creates an accumulation of better original survey data for surveyors with added benefits.

Benefits of TMLS Surveyors must approach this proven technology as a way to solve problems in the field. Many organizations are suffering from key standards for safety, efficiency, and accuracy, and mobile 3D laser scanning addresses those standards in the following ways.

Safety: Survey-grade road surface documentation at highway speeds improves safety and efficiency for both traveling public and the surveyor in the next ways. It:
? eliminates road/lane closures,
? reduces traffic disruption,
? finishes the project more quickly than traditional methods,
? is a safer method of data collection, and
? keeps the surveyor out of the red zone.

Efficiency: Because in-house surveyors supply control and check shots through traditional methods, efficiency is increased,and the ones benefits can be passed through to the client through:
? acceleration of the look project schedule through faster field data collection,
? deliverables created through in-house technicians,
? data designed for extraction, when needed, how needed, where needed, and
? control of the info remaining in-house.

Accuracy: TMLS is a proven technology. Evaluations performed at a Caltrans test area specifically designed to judge mobile laser scanning systems led to an RMS error of 0.022'. The route chosen was to permit companies advanced in mobile laser scanning technology an independent evaluation against CalTrans total station collected points.

Implementing TMLS
Many surveyors have mastered only 1 method of performing surveying operations, and they have to expand their horizons by learning multiple software packages for field-to-finish and office computations. There are a variety of new services a normal surveyor can add to the profession to expand business through TMLS. Surveyors who acquired scanners originally to perform traditional surveys and inspections are carving their own niche in the market through accident reconstruction surveys. Companies which have been doing forensic work with years have discovered that laser scanning enables them to perform investigations faster and more thoroughly, and mere access to scanner data is keeping them prior to the competition when bidding for new jobs.

Previously, the airborne industry has documented nearly all overhead line surveys. With mobile 3D laser scanning, wires down to 3mm in diameter can be accurately located and their heights measured. The data allows for calculations of sway and sag of overhead power lines. The price to the client between airborne and mobile surveying is really a drastic reduction. What the "fly-by" replaced in speed from traditional methods, the "drive-by" added benefits in expense. TMLS technology, just like the StreetMapper system out from the United Kingdom, can simply be adapted within less than an hour to vessels providing high-resolution coastal land surveys of upland features, including dunes, beach cusps, scarps, and vegetation. The 3D laser scanning resolution far exceeds whatever can be acquired through traditional surveying methods. This allows for surveys of unprecedented detail.

Rapid data acquisition through TMLS enables the generation of 3D city models to be used for homeland security issues and evacuation planning. Colorization of models are benefits to planning boards and marketing city attractions and expansion. City modeling is rapidly becoming a significant catalyst for data acquisition through technologies such as Google Earth and MapQuest.

Rail construction tasks require reliable survey data. Because of highly increasing traffic load, combined with age structure of the rail network, responsible administrations are forced to place the primary emphasis of maintenance activities into projects to ensure quality, safety, and sufficient traffic capacity. The negative influences of maintenance tasks must be kept as small as possible. This is a lot more important for the necessary substantial engineering/survey work that's needed in advance to capture basic data for construction planning and preparation. TMLS mounted on a hyrailer minimizes the survey effort to capture the required data along existing railways.

Only a comparatively short driving time is needed for data collection, while the traffic flow isn't significantly affected. This process reduces both costs and safety risks.Three-dimensional airport surveys captured by TMLS empower engineers and land surveying crews with scan data of runway surfaces, building footprints, measure distance, sign identification, and locations along with survey terminals, taxiways,and aprons, all without disruption to air traffic.

Automated permitting for truck routing for bridge heights and clearances by traditional survey methods is costly, time consuming, and presents difficult in managing the changing data due to continued highway construction resurfacing projects. Obtaining survey-grade accuracy for bridge heights and clearances at traffic speeds is the most efficient way to measure various structures and roadway features. Accuracies of better than 1/2" have already been obtained for vertical clearances of roadway structures. It really is critically important in oversize route planning. Horizontal clearance measurements must be maintained. Collecting this data in a traditional manner could be dangerous or can cause congestion with work crews at the mercy of serious traffic hazards. Work must be performed during available traffic breaks, which can introduce errors. From the system-wide perspective, clearance information in many cases is incomplete, inaccurate, and difficult to keep up and to access.

Highway surveys with mobile 3D laser scanning are used for maintenance and asset management of road surface and street configurations by identifying concrete spalling and pitting. Construction monitoring can also be obtained for forensic identification of rebar placement before a pour. This data allows for complete surface contour capabilities of road crowning and rutting measurements.

Mark Coon, LS, a geospatial manager at Erdman Anthony, says, "We currently use Terrestrial LiDAR on highway and bridge surveys for the NYSDOT, and it's obvious that mobile lidar could be the technology of choice eventually."

These are just some of the ways the surveying profession can enhance their services using TMLS as another tool within their toolbox. Surveyors who understand and accurately position themselves to react to these technology advancements will remain prior to the concerns of an otherwise seemingly dying breed.